Sure thing, let's get straight to it. We start with 777 and we're going to multiply it by 100, which means adding 777 to itself 100 times.
Step 1: 0 + 777 = 777
Step 2: 777 + 777 = 1554
Step 3: 1554 + 777 = 2331
Step 4: 2331 + 777 = 3108
Step 5: 3108 + 777 = 3885
Step 6: 3885 + 777 = 4662
Step 7: 4662 + 777 = 5439
Step 8: 5439 + 777 = 6216
Step 9: 6216 + 777 = 6993
Step 10: 6993 + 777 = 7770
Step 11: 7770 + 777 = 8547
Step 12: 8547 + 777 = 9324
Step 13: 9324 + 777 = 10101
Step 14: 10101 + 777 = 10878
Step 15: 10878 + 777 = 11655
Step 16: 11655 + 777 = 12432
Step 17: 12432 + 777 = 13209
Step 18: 13209 + 777 = 13986
Step 19: 13986 + 777 = 14763
Step 20: 14763 + 777 = 15540
Step 21: 15540 + 777 = 16317
Step 22: 16317 + 777 = 17094
Step 23: 17094 + 777 = 17871
Step 24: 17871 + 777 = 18648
Step 25: 18648 + 777 = 19425
Step 26: 19425 + 777 = 20202
Step 27: 20202 + 777 = 20979
Step 28: 20979 + 777 = 21756
Step 29: 21756 + 777 = 22533
Step 30: 22533 + 777 = 23310
Step 31: 23310 + 777 = 24087
Step 32: 24087 + 777 = 24864
Step 33: 24864 + 777 = 25641
Step 34: 25641 + 777 = 26418
Step 35: 26418 + 777 = 27195
Step 36: 27195 + 777 = 27972
Step 37: 27972 + 777 = 28749
Step 38: 28749 + 777 = 29526
Step 39: 29526 + 777 = 30303
Step 40: 30303 + 777 = 31080
Step 41: 31080 + 777 = 31857
Step 42: 31857 + 777 = 32634
Step 43: 32634 + 777 = 33411
Step 44: 33411 + 777 = 34188
Step 45: 34188 + 777 = 34965
Step 46: 34965 + 777 = 35742
Step 47: 35742 + 777 = 36519
Step 48: 36519 + 777 = 37296
Step 49: 37296 + 777 = 38073
Step 50: 38073 + 777 = 38850
Step 51: 38850 + 777 = 39627
Step 52: 39627 + 777 = 40404
Step 53: 40404 + 777 = 41181
Step 54: 41181 + 777 = 41958
Step 55: 41958 + 777 = 42735
Step 56: 42735 + 777 = 43512
Step 57: 43512 + 777 = 44289
Step 58: 44289 + 777 = 45066
Step 59: 45066 + 777 = 45843
Step 60: 45843 + 777 = 46620
Step 61: 46620 + 777 = 47397
Step 62: 47397 + 777 = 48174
Step 63: 48174 + 777 = 48951
Step 64: 48951 + 777 = 49728
Step 65: 49728 + 777 = 50505
Step 66: 50505 + 777 = 51282
Step 67: 51282 + 777 = 52059
Step 68: 52059 + 777 = 52836
Step 69: 52836 + 777 = 53613
Step 70: 53613 + 777 = 54390
Step 71: 54390 + 777 = 55167
Step 72: 55167 + 777 = 55944
Step 73: 55944 + 777 = 56721
Step 74: 56721 + 777 = 57498
Step 75: 57498 + 777 = 58275
Step 76: 58275 + 777 = 59052
Step 77: 59052 + 777 = 59829
Step 78: 59829 + 777 = 60606
Step 79: 60606 + 777 = 61383
Step 80: 61383 + 777 = 62160
Step 81: 62160 + 777 = 62937
Step 82: 62937 + 777 = 63714
Step 83: 63714 + 777 = 64491
Step 84: 64491 + 777 = 65268
Step 85: 65268 + 777 = 66045
Step 86: 66045 + 777 = 66822
Step 87: 66822 + 777 = 67599
Step 88: 67599 + 777 = 68376
Step 89: 68376 + 777 = 69153
Step 90: 69153 + 777 = 69930
Step 91: 69930 + 777 = 70707
Step 92: 70707 + 777 = 71484
Step 93: 71484 + 777 = 72261
Step 94: 72261 + 777 = 73038
Step 95: 73038 + 777 = 73815
Step 96: 73815 + 777 = 74592
Step 97: 74592 + 777 = 75369
Step 98: 75369 + 777 = 76146
Step 99: 76146 + 777 = 76923
Step 100: 76923 + 777 = 77700

So, 777*100 = 77700